Rock Identifier

Category

Sedimentary (Biogenic)

Browse sedimentary (biogenic) specimens identified by the Rock Identifier community.

Ironstone Concretion / Goethite Nodules (Ironstone (composed primarily of Goethite FeO(OH) and Limonite)) — sedimentary

Ironstone Concretion / Goethite Nodules

Ironstone (composed primarily of Goethite FeO(OH) and Limonite)

Siltstone (Siltstone (primarily composed of SiO2, Al2O3, and phyllosilicates)) — sedimentary

Siltstone

Siltstone (primarily composed of SiO2, Al2O3, and phyllosilicates)

Red Ochre (Hematite-rich Clay) (Limonitic/Hematitic Claystone (Fe2O3 with clay minerals)) — Sedimentary

Red Ochre (Hematite-rich Clay)

Limonitic/Hematitic Claystone (Fe2O3 with clay minerals)

Limestone (specifically Fossiliferous or Crinoidal Limestone) (Calcium Carbonate (CaCO3) - Calcite Rock) — sedimentary

Limestone (specifically Fossiliferous or Crinoidal Limestone)

Calcium Carbonate (CaCO3) - Calcite Rock

Red Sandstone (Clastic sedimentary rock (primarily Quartz and Feldspar with Iron Oxide cement)) — sedimentary

Red Sandstone

Clastic sedimentary rock (primarily Quartz and Feldspar with Iron Oxide cement)

Red Sandstone (Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)) — sedimentary

Red Sandstone

Clastic Sedimentary Mineraloid (predominantly Quartz grains with Iron Oxide cement)

River Stone (likely Mudstone or Siltstone) (Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)) — sedimentary

River Stone (likely Mudstone or Siltstone)

Lutite (Clastic sedimentary rock composed of clay and silt-sized particles)

Red Hematite (Iron(III) oxide (Fe2O3)) — mineral

Red Hematite

Iron(III) oxide (Fe2O3)

Limonite (Iron Ore) (FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)) — mineral

Limonite (Iron Ore)

FeO(OH)·nH2O (Hydrated iron(III) oxide-hydroxide)

Ferruginous Sandstone (Sandstone (rich in iron oxides/hydroxides)) — sedimentary

Ferruginous Sandstone

Sandstone (rich in iron oxides/hydroxides)

Red Jasper (Jasper) (Silicon Dioxide (SiO₂)) — sedimentary

Red Jasper (Jasper)

Silicon Dioxide (SiO₂)

Siltstone (Siltstone (primarily composed of microcrystalline Quartz and Feldspar)) — sedimentary

Siltstone

Siltstone (primarily composed of microcrystalline Quartz and Feldspar)

Siltstone with Quartz Vein (Siltstone (primarily SiO2, Al2O3, Fe2O3)) — sedimentary

Siltstone with Quartz Vein

Siltstone (primarily SiO2, Al2O3, Fe2O3)

Fossil Sand Dollar (Echinoidea) (Phylum Echinodermata, Class Echinoidea (likely Dendraster or Scutella)) — sedimentary

Fossil Sand Dollar (Echinoidea)

Phylum Echinodermata, Class Echinoidea (likely Dendraster or Scutella)

Chert (Nodular) (Chert (SiO2 - Microcrystalline Quartz)) — sedimentary

Chert (Nodular)

Chert (SiO2 - Microcrystalline Quartz)

Chert / Flint (Cryptocrystalline Quartz (Silicon Dioxide, SiO2)) — sedimentary

Chert / Flint

Cryptocrystalline Quartz (Silicon Dioxide, SiO2)

Fossiliferous Limestone (Chertified Limestone) (Calcium Carbonate (CaCO3) often replaced by Microcrystalline Silica (SiO2)) — sedimentary

Fossiliferous Limestone (Chertified Limestone)

Calcium Carbonate (CaCO3) often replaced by Microcrystalline Silica (SiO2)

Jasper Conglomerate (Puddingstone) (Siliceous Conglomerate (Quartz and Jasper clasts in a fine-grained matrix)) — sedimentary

Jasper Conglomerate (Puddingstone)

Siliceous Conglomerate (Quartz and Jasper clasts in a fine-grained matrix)

Chert (Jasper variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Amber (Succinite) — mineral

Amber

Succinite

Quartz / Quartzite (Silicon Dioxide (SiO2)) — metamorphic

Quartz / Quartzite

Silicon Dioxide (SiO2)

Limonite (Ironstone) (Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)) — mineral

Limonite (Ironstone)

Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)

Red Quartzite (Quartzite (SiO2)) — metamorphic

Red Quartzite

Quartzite (SiO2)

Zebra Jasper (Silicon dioxide (SiO2) with various impurities) — Sedimentary

Zebra Jasper

Silicon dioxide (SiO2) with various impurities

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Sand Dollar Fossil (Echinoidea) (Class Echinoidea (likely order Clypeasteroida), CaCO3 (Calcite)) — sedimentary

Sand Dollar Fossil (Echinoidea)

Class Echinoidea (likely order Clypeasteroida), CaCO3 (Calcite)

Quartz Druze on Matrix (Silicon Dioxide (SiO2)) — mineral

Quartz Druze on Matrix

Silicon Dioxide (SiO2)

Limonite (Iron Ore) (Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)) — Mineral

Limonite (Iron Ore)

Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)

Yellow Quartzite (or Quartz River Pebble) (Silicon Dioxide (SiO2)) — metamorphic

Yellow Quartzite (or Quartz River Pebble)

Silicon Dioxide (SiO2)

Amber (Amber (C10H16O)) — mineral

Amber

Amber (C10H16O)

Amber (Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)) — Organic Mineraloid

Amber

Succinite (specifically for Baltic amber); Fossilized Tree Resin (C10H16O)

Organic Mineraloid

Quartzite (clastic/metamorphic subtype) (Quartzite (primarily Silicon Dioxide, SiO2)) — metamorphic

Quartzite (clastic/metamorphic subtype)

Quartzite (primarily Silicon Dioxide, SiO2)

Petrified Wood (Silicified Wood (SiO2)) — metamorphic

Petrified Wood

Silicified Wood (SiO2)

Red Jasper (Brecciated or Mottled) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Red Jasper (Brecciated or Mottled)

Silicon Dioxide (SiO2) with iron oxide inclusions

Ferruginous Sandstone (Ironstone) (Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)) — sedimentary

Ferruginous Sandstone (Ironstone)

Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)

Chert (Chert / Flint) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Chert / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Chalcedony (Silicon Dioxide (SiO2)) — mineral

Chalcedony

Silicon Dioxide (SiO2)

Chert (varietal Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (varietal Flint)

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold) (Iron Disulfide (FeS2)) — mineral

Pyrite (Fool's Gold)

Iron Disulfide (FeS2)

Magnetite (Lodestone) (Magnetite (Fe3O4)) — mineral

Magnetite (Lodestone)

Magnetite (Fe3O4)

Sandstone Concretion (Ferruginous Sandstone Concretion) — sedimentary

Sandstone Concretion

Ferruginous Sandstone Concretion